<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        ul {
            width: 500px;
            height: 100px;
            list-style: none;
            background: forestgreen;
            margin: 0 auto;
        }
        li {
            width: 20%;
            /* 浮动 */
            float: left;
            background: yellow;
            text-align: center;
            margin-right: 20px;
        }
        li a {
            text-decoration: none;
            color: black;
            line-height: 3;
        }
    </style>
</head>
<body>
    <ul>
        <li><a href="">111</a></li>
        <li><a href="">222</a></li>
        <li><a href="">444</a></li>
    </ul>
    <div style="background: teal;">sdkkkdfooosssdd</div>
</body>
</html>